sounds like a short to me...find the short or ground problem by tracing your wires down from the bar to under the tank.It might be possible to fix the short with some butt connectors,if all else fails,a new switch would be the next step.The new switch should fix the intermitent workings.If you get an OEM kill switch,it is just a matter of unplugging the old and plugging in the new.Stalling the bike should'nt really bother the bike short term,over the long though it might cause some issues,what they might be I am not sure.I would either fix the old or get a new switch.Cheers.